1645245873 has 24 divisors (see below), whose sum is σ = 2518582248. Its totient is φ = 1031357952.

The previous prime is 1645245869. The next prime is 1645245881. The reversal of 1645245873 is 3785425461.

1645245873 is a `hidden beast` number, since 1 + 6 + 4 + 524 + 58 + 73 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 244390689 + 1400855184 = 15633^2 + 37428^2 .

It is not a de Polignac number, because 1645245873 - 2² = 1645245869 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1645245373) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 184915 + ... + 193607.

It is an arithmetic number, because the mean of its divisors is an integer number (104940927).

Almost surely, 2^1645245873 is an apocalyptic number.

It is an amenable number.

1645245873 is a deficient number, since it is larger than the sum of its proper divisors (873336375).

1645245873 is a wasteful number, since it uses less digits than its factorization.

1645245873 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9953 (or 9950 counting only the distinct ones).

The product of its digits is 806400, while the sum is 45.

The square root of 1645245873 is about 40561.6305515446. The cubic root of 1645245873 is about 1180.5297518425.

The spelling of 1645245873 in words is "one billion, six hundred forty-five million, two hundred forty-five thousand, eight hundred seventy-three".